[GBSB (OP)]

EVOLUTION OF THE HUMAN BODY POSTURE

As long as we can trace the history of human beings, we can see that there were two main activities which were necessary to perform in order for humans to be able to survive.  
One of these activities was moving from one place to another (walking, running or jumping).
Another activity was to carry goods (mainly in the hands or on the shoulders.)
Like no other species, humans were carrying goods mainly on the shoulders and in the hands.
 
Till recently, human’s rarely traveled, even for small distances, without carrying some goods in the hands or on the shoulders.

The two main things that human beings had to take care of when moving (walking, running and occasionally jumping) from one place to another was, where he is stepping and how he is transferring body weight from one leg to another, with the intention not to hurt the surface of the bottom of the feet and not to lose balance (if he losses balance, he will fall on the ground). Because of that, he was transferring his body weight form one leg to another carefully and independently from the speed of the movement.
 
These two activities (traveling and at the same time carrying goods on the shoulders and/or in the hands) have big influences in forming the body posture. Because of that, the way of the body posture, from the bottom of the feet to the top of the shoulder, has evolved to be able to carry goods in the hands and on the shoulders, and at the same time be able to maintain balance.
 
Carrying the goods was one important activity which guided the evolution of the human body posture.
 
By doing this activity, the environment demanded from the human to see where he was going and where he was stepping.
The holding of the head and the neck has developed in such a way that he can with a minimum movement of the head, to see where he is stepping and where he is going. Because of that, his neck and head was slightly leaning forward.
For example, when walking through a forest, we need to be able to see where we are going and where we are stepping. The time span between looking in the direction where we are going and looking on the ground where we are stepping must be short. Because if we watch for too long where we are stepping, we will in a short time hit the tree and if we watch too long where we are going, we will in a short time trip on the birch or some other objects which is lying on the ground. As we change our focus in a short time, from where we are going and where we are stepping, the head and the neck from itself starts to lean slightly forward to enable us to see where we are going and where we are stepping, by mainly just moving our eyes with a minimum movement of the head.

If we walk through a forest without carrying some weight in the hands and on the shoulders, we can still do that with the many different types of body postures, concerning the body from the bottom of the feet to the top of the shoulders.
 
But if we carry some weight on the shoulders, or in the hands, in the long term we can do this activity only if our body from the bottom of the feet to the top of the shoulder is in an upright position and the neck with the head is in a relaxed slightly forward leaning position.
 
Carrying some goods on the shoulder and in the hands was an important contributing factor in gaining and maintaining physical strength and physical balance of the human body, and it was also a contributing factor in the evolution of the human race.  

Luka Tunjic

http://www.freewebs.com/lukatunjic/

[tony6789]

actually there r hunchbacks



NEVER! underestimate youth

[GordonP]

I wonder what caused a particular species of ape to evolve an upright posture in the first place and what was the driving evolutionary force that totally changed the hip bone of this particular species.

G W Pipes

[GordonP]

PS
All the other apes survived without walking upright so it was not a survival response.

G W Pipes

[neilep]

This is an interesting topic.

I would have thought that it was a necessity for us to stand upright was at least two fold.

1. Being upright is an invaluable ability for protection from being hunted

2. In contrast , being upright is a distinct advantage when it comes to hunting as the taller you are the further you can see unsuspecting dinner !!

..additionally, being upright helps to serve to reach higher fruits from trees etc.

Walking upright was probably one of the main landmarks that set us apart from the other apes. This must have contributed enormously to the manner in which our evolution was affected.



Men are the same as women, just inside out !

[another_someone]

quote:Originally posted by GordonP
I wonder what caused a particular species of ape to evolve an upright posture in the first place and what was the driving evolutionary force that totally changed the hip bone of this particular species.

Caused or allowed?

The normal assumption about evolution is that it is caused by random mutations, and some of these random mutations then prove to be useful in certain niches and this allows the mutated individuals to survive and thrive, and thus create a new species based upon those mutations.

First question – what are the disadvantages of a bipedal stance, and why have the other apes not taken it up?

One obvious disadvantage is the need for relatively flat feat that are convenient when one walks on flat ground, but would be problematic when climbing trees.  Humans have not only flat feet, but relatively flat hands, which again makes the hands more flexible in many ways, but although the hands can be used to grip branches, they probably need more effort to do so because their relaxed state is to be almost flat palmed.

A long, upright, body also exposes much of the front of the body to attack in a way that a body walking on four limbs does not.  On the other hand, a long upright body allows one to see further over open ground, as well as being more streamlined in the water.

George

[GordonP]

quote:Originally posted by neilep

This is an interesting topic.

I would have thought that it was a necessity for us to stand upright was at least two fold.

1. Being upright is an invaluable ability for protection from being hunted

2. In contrast , being upright is a distinct advantage when it comes to hunting as the taller you are the further you can see unsuspecting dinner !!

..additionally, being upright helps to serve to reach higher fruits from trees etc.

Walking upright was probably one of the main landmarks that set us apart from the other apes. This must have contributed enormously to the manner in which our evolution was affected.



Men are the same as women, just inside out !

G W Pipes

[GordonP]

1 Why?

G W Pipes

[GordonP]

2 seeing dinner is one thing, eating it another. Addtionaly climbing trees allows you to feed near the top of the tree.

G W Pipes

[GordonP]

Hi George
Humans evolved flat feet, presumably while they were evolving a pelvic bone that allowed them to stand upright. Why?

G W Pipes

[neilep]

Hi Gordon,

Standing upright doesn't preclude you from climbing trees still !

To answer your query and these are just my own conclusions, but standing upright enables you to see predators from farther away and also to peer down into high grass to see squatting predators about to pounce !...in my opinion of course....so you get an early warning..

...and seeing dinner from further away , I would have thought would expand your chances of seeking dinner, due to the wider field of view....but as I said..these are just my thoughts.....

Men are the same as women, just inside out !

[GordonP]

Hi Neilep
Standing upright offers no advantages over an ape sitting high in a tree.

The question is. Why did one particular species of ape abandon the safety of the trees for a life on the ground? Remember although evolution, given the right circumstances, can happen comparitively quickly, this species of ape must have survived on the ground for thousands of years before the transformation of the pelivic bone was complete. How did this species survive for long enough for the process to reach completion?

G W Pipes

[another_someone]

quote:Originally posted by GordonP

Hi Neilep
Standing upright offers no advantages over an ape sitting high in a tree.

The question is. Why did one particular species of ape abandon the safety of the trees for a life on the ground? Remember although evolution, given the right circumstances, can happen comparitively quickly, this species of ape must have survived on the ground for thousands of years before the transformation of the pelivic bone was complete. How did this species survive for long enough for the process to reach completion?

G W Pipes

One would presume because proto-human suddenly found himself in a place that lacked trees, so the choice of running up a tree for safety simply did not occur.

Could be climatic change that reduced trees; could be overcrowding that forced some apes out of the forest; or it could be some calamity that left some proto-humans stranded away from their traditional habitat.

George

[neilep]

Hi Gordon (nice homepage..I'll have to read that when I get a chance..but it looks fascinating !..see ?...everybody will look at it now !! [])...oh !..call me Neil !

You ask a very good question...I just wish I had an answer to complement it []

I just do not know......circumstance and necessity leads to invention  and evolution...something must have happened to a breed of ape that ,where ever they were located on Earth at the time, the surrounding geography must have imposed/coerced this evolutionary progress which, must have been specific to that area ..it must have dictated over time the evolution of the ability to stand upright....

without the benefit of a time machine I guess we'll never know unless irrefutable proof is discovered.

Do you have any theories on the matter ?

Men are the same as women, just inside out !

[another_someone]

quote:Originally posted by GordonP
2 seeing dinner is one thing, eating it another. Addtionaly climbing trees allows you to feed near the top of the tree.

G W Pipes

Rather depends upon what you consider to be dinner.

If your happy eating fruit and veg, then the top of a tree is fine, but if you want some meat in your diet, then there is a limit to what you can have at the top of the tree.

Even Chimpanzees rather like a mixed diet, although Gorillas seem to be happy with a strictly vegetarian diet, with a few insects (although, interestingly gorillas are rather large for climbing trees).

George

[GordonP]

I don't think so George, the climatic change that affected North Africa when the sub-continent of India came into contact with Ero-Asia must have happened slowly enough for all the apes to follow the retreating trees into central Africa. We are still talking about a massively large area of jungle, big enough for all the apes.

Why did our ancestors stay behind? And how did they survive long enough to evolve into the human species?



G W Pipes

[GordonP]

Meat eaters are, by and large, preditors. Preditors are, by and large top of the food chain. How did an ape get there?

G W Pipes

[another_someone]

quote:Originally posted by GordonP

I don't think so George, the climatic change that affected North Africa when the sub-continent of India came into contact with Ero-Asia must have happened slowly enough for all the apes to follow the retreating trees into central Africa. We are still talking about a massively large area of jungle, big enough for all the apes.

Why did our ancestors stay behind? And how did they survive long enough to evolve into the human species?

G W Pipes

Speciation does not happen across a continent.  In order for a new species start out, it has to occur in a very small geographic area.  Even if the mass of apes were to be able to follow the retreating trees, one would expect individual communities to become separated from the mass retreat.

Nor can it be said that there is ever enough forest/jungle for all the apes.  The nature of all species is that they will expand their population to utilise all the resources at their disposal.  Since it is the nature of the ecosystem that there are times when available resources are increasing (allowing an increase in population), and times when resources reduce (causing pressure on the population).  It would thus seem perfectly normal that in one of these period of expanding resources, the population of apes would expand to utilise these resources; but then when resources started to become more restricted, some of this large population of apes suddenly found they did not have the resources to live on, and had to look for new resources.

The Indian subcontinent actually started colliding with Asia around 55 million years ago, long before the proto-humans separated from other apes.  Apes themselves only separated from other monkeys around 25 million years ago, and humans from other apes about 7 million years ago.  Over those 7 million years, there have been many changes in climate, for all sorts of reasons, many of which are not even fully understood.  I don't know what was the direction of global climate change, let alone local climate change, was at the time when proto-humans separated from other apes.

George

[another_someone]

quote:Originally posted by GordonP
Meat eaters are, by and large, preditors. Preditors are, by and large top of the food chain. How did an ape get there?

So fasciitis necroticans or Clostridium botulinum are at the top of the food chain?

I think it is a little simplistic to look at the 'food chain' as a structure that has a clear top and a clear bottom.

This is ofcourse even further complicated by animals that indulge in cannibalism (which includes both some human tribes and chimpanzees).  Are animals who eat their own kind above or below themselves in the food chain?

George

[GordonP]

Hi again George
Where ever, or when ever, apes began to walk upright, it happened. Even Darwin couldn't tell us why. In 2006 one-one else can.

How does an ape, so dependent on trees for survival, suddenly survive on the open grasslands?

One possible answer to this question is so politically incorrect, so soaked in sex and violence, that I hesitate to offer it before properly examining other explainations.

Please help me out, offer me an explaination.

G W Pipes